1. Field of the Invention
The present invention relates to a lens-fitted photo film unit of a waterproof type and a disassembling method for the same. More particularly, the present invention relates to a lens-fitted photo film unit of a waterproof type which can be disassembled easily and safely, and a disassembling method for the same.
2. Description Related to the Prior Art
A lens-fitted photo film unit is pre-loaded with photo film, and sold and used widely because of its great ease in handling and low price. There are various types of the lens-fitted photo film unit adapted to kinds of scenes and situations to be photographed in different manners. For example, a waterproof type of the lens-fitted photo film unit is known for the purpose of underwater photography. This type is constituted by the lens-fitted photo film unit and a waterproof case for containing the lens-fitted photo film unit in a watertight manner. A shutter mechanism in the lens-fitted photo film unit is operable by use of a mechanism disposed through the waterproof case.
The waterproof case as an element of the waterproof type is constituted by a front containing member, a rear containing member and a rubber packing. The front and rear containing members are respectively formed from transparent resin, and fitted on one another in a watertight manner with the rubber packing inserted between those. After all exposures are taken in the lens-fitted photo film unit in the waterproof case, the lens-fitted photo film unit as contained in the waterproof case is forwarded to a photo laboratory. Then a photofinishing operator separates the front and rear containing members from one another and removes the lens-fitted photo film unit from the waterproof case. The exposed photo film from the lens-fitted photo film unit is developed and subjected to printing.
To remove the lens-fitted photo film unit from the waterproof case, there is a small thickness portion formed in either of the front and rear containing members of the waterproof case with a smaller thickness. A process of the removal is as follows: At first, a separator tool, such as a screwdriver of a minus-shaped end, is used to break through the small thickness portion. The end of the separator tool is inserted in the waterproof case. The end of the separator tool is engaged with a lateral side of the lens-fitted photo film unit, and forcibly moved to push the lens-fitted photo film unit out of the waterproof case. Thus, the lens-fitted photo film unit and front containing member are removed together from the rear containing member, or the lens-fitted photo film unit and rear containing member are removed together from the front containing member.
However, there is a problem in the known type of the waterproof case in that operators hands treating the separator tool are likely to be injured by the end of the separator tool, because the separator tool may be slipped from the hands. There is a difficulty in exactly handling the separator tool, as the small thickness portion of the waterproof case of a very small size must be penetrated by the separator tool, and the forcibly moving operation for the separator tool must be precise.
In view of the foregoing problems, an object of the present invention is to provide a lens-fitted photo film unit of a waterproof type in which a waterproof case can be disassembled easily and safely to take photo film out of the lens-fitted photo film unit, and a disassembling method for the same.
In order to achieve the above and other objects and advantages of this invention, a waterproof lens-fitted photo film unit includes a lens-fitted photo film unit. First and second containing members contain the lens-fitted photo film unit therebetween in a watertight manner. A separation opening is formed in the first containing member. A separation access chamber has an entrance connected to the separation opening, and closes the separation opening in a watertight manner in a position interior with reference to the first containing member. The separation access chamber includes a thin wall having a small thickness, and being breakable by a separator member having a long shape with a small width.
The second containing member is positioned on the first containing member in a first direction and fitted together. The thin wall is disposed in the first direction from a portion of the lens-fitted photo film unit oriented in the first direction, and broken through by the separator member. The lens-fitted photo film unit is pushed in a second direction opposite to the first direction by the separator member penetrating the first containing member, to separate the first containing member from the second containing member.
The thin wall is formed to project from an edge of the separation opening. The separation access chamber further includes an erect wall formed to project from a position in the edge of the separation opening opposite to the thin wall. A reinforcing projection is formed with the erect wall to project toward the thin wall, adapted to pivotal movement of the separator member about a fulcrum defined on a surface thereof, to break through the thin wall.
The first containing member includes a first case wall disposed outside one face of the lens-fitted photo film unit oriented in the first direction. A second case wall extends from the first case wall in the second direction, and is disposed outside one face of the lens-fitted photo film unit. The separation opening is formed in the second case wall and disposed close to the first case wall. The erect wall is constituted by a portion of the first case wall.
Furthermore, a receiving recess is formed in the lens-fitted photo film unit, disposed close to the thin wall, and pushed by the separator member after the separator member breaks through the thin wall.
The first direction is a forward direction. The first containing member is a case body of which a rear is open. The second containing member is a rear lid for closing the rear of the case body in a watertight manner.
In a disassembling method for the waterproof lens-fitted photo film unit, a separator member having a long shape with a small width is inserted in the separation opening. The thin wall is broken through by pivotally moving the separator member about a fulcrum defined on an edge of the separation opening. After breaking of the separator member through the thin wall, the first containing member is separated from the second containing member with the separator member.
The second containing member is positioned on the first containing member in a first direction and fitted together. The thin wall is disposed in the first direction from a portion of the lens-fitted photo film unit oriented in the first direction, and broken through by the separator member. The separating step includes pushing the lens-fitted photo film unit in a second direction opposite to the first direction by pivotally moving the separator member about a fulcrum defined on the edge of the separation opening while the separator member penetrates the first containing member.
According to another aspect of the present invention, a waterproof lens-fitted photo film unit includes a lens-fitted photo film unit. First and second containing members contain the lens-fitted photo film unit therebetween in a watertight manner. A separation engaging portion is formed to project from or retreat from an outer surface of the first containing member, and engageable with a separator member. A thin portion is formed around the separation engaging portion, has a small thickness, and is breakable upon operation of the separator member to the separation engaging portion.
The separator member has a long shape with a small width, and has a driving surface oriented in a prescribed direction with reference to an axial direction thereof. The separation engaging portion has a driven surface engaged with the driving surface, and rotated by the separator member.
The first containing member includes a first case wall disposed outside one face of the lens-fitted photo film unit oriented in the first direction. A second case wall extends from the first case wall in the second direction, and is disposed outside one face of the lens-fitted photo film unit. The thin portion is formed in the second case wall and disposed close to the first case wall.
A ring-shaped groove is formed in the first containing member around the separation engaging portion, and has a bottom constituting the thin portion.
The separation engaging portion has a shape rotationally symmetrical about one rotational center.
The separation engaging portion includes plural recesses extending radially from the rotational center, and having an inner surface constituting the driven surface.
The thin portion has a thickness of 0.3-0.7 mm.
In a disassembling method for the waterproof lens-fitted photo film unit, a separator member is engaged with the separation engaging portion. The thin portion is broken by rotating the separator member. The separator member is caused to penetrate the first containing member through a broken position of the thin portion. While the separator member penetrates the first containing member, the first containing member is separated from the second containing member with the separator member.
The separator member includes a separator end portion having a plate shape with a small thickness, and having the driving surface.